WordNet sense 1 (yet to be or coming):

future

WordNet sense 2 (belonging to the distant past):

former, other

WordNet sense 3 ((used of living things especially persons) in an early period of life or development or growth):

immature, young

WordNet sense 4 (appearing or developing early):

precocious

WordNet sense 5 (belonging to an early stage of technical development; characterized by simplicity and (often) crudeness):

primitive

WordNet sense 6 ((of crops) harvested at an early stage of development; before complete maturity):

new

WordNet sense 7 (too soon or too hasty):

premature, previous

WordNet sense 8 (having existed from the beginning; in an earliest or original stage or state):

primal, primeval, primordial

WordNet sense 9 (during an early stage):

early on

WordNet sense 10 (in good time):

betimes

WordNet sense 11 (before the usual time or the time expected):

ahead of time, too soon